Cephalosporin antibiotics inhibit bacteria by interfering with the synthesis of essential structural components of the bacterial cell wall. They are considered as highly effective antibiotics with low toxicity and are used for treating a wide variety of bacterial infections.
Cephalosporin C was isolated in 1952 from a mold of the genus Cephalosporium. A decade later the nucleus (7-aminocephalosporanic acid) was isolated and used as the basis for a series of synthetic derivatives, including cephalothin, cephaloridine and cephaloglycin.
Research has provided many cephalosporin derivatives with increased potency and improved stability. For example, derivatives containing a 7-aminothiazolyl group such as cefotiam have been shown to have increased potency. Resistance to .beta.-lactamase has been found to be conferred by a methoximino group at the alpha carbon atom in the 7-acyl group. Several cephalosporins have been developed that have combined these structural features to provide highly potent enzyme resistant compounds; e.g. cefotaxime, cefmenoxime, ceftizoxime, and ceftriaxon.
Ochiai et al. (U.S. Pat. No. 4,098,888 granted Jul. 4, 1978) describe cephem compounds and processes for their preparation. Heymes et al. (U.S. Pat. No. 4,152,432) describe 3-acetoxymethyl-7-(iminoacetamido) cephalosporanic acid derivatives, in particular cefotaxime, and processes for preparing the derivatives.